Forced flow ventilator



United States Patent O 3,212,425 FORCED FLOW vENmAron John 0. Hazen, Monaca, and Robert G. Lindner, Bridgeville, Pa., assignors to H. H. Robertson Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed June 22, 1962, Ser. No. 204,575 6 Claims. (Cl. 98-43) This invention relates to a forced llow ventilator and more particularly to a forced flow ventilator having freely pivotal dampers for sealing the ventilator gas passageways when the fan is not operating.

According to the present invention, a ventilator is provided having a ventilator stack which terminates in an external flange at its upper edge. The stack is adapted to surround a curb of a ventilator opening in a roof of a building. A cap member is maintained upwardly spaced from the stack by means of vertical support members. A fan and its associated drive means are mounted within the stack for withdrawing gases from the interior of the building.

In the present invention, the gases to be exhausted are drawn through the stack and are subsequently discharged horizontally through at least one gas passageway. The gas passageway is positioned between at least one adjacent pair of the vertical support members and above the external flange and below the cap member.

T-o seal the gas passageways when the fan is not operating, a substantially vertically disposed damper is provided which is substantially the same size as the gas passageway. The damper is positioned externally of the gas passageway and is pivotally secured along its upper edge to the adjacent pair of vertical support members. The damper has magnet means secured thereto, preferably on the external surface thereof, which are adapted to be attracted to portions of the ventilator structure surrounding the gas passageway. The magnet means have sufficient strength to hold the damper in sealing relation with the gas passageway only when the fan is not operating. When the fan is started, the built-up gas pressure within the ventilator forces the damper outwardly thereby permitting the exhaustion of the gases. The damper preferably is fabricated from lightweight, relatively thin gauge aluminum.

The damper also is provided with an outwardly extending flashing member along its bottom edge. The flashing member serves three functions. Namely, (a) it serves to seal the lower edge of the gas passageway when the damper is in a closed position by engaging the external flange; (b) it serves to maintain the damper spaced from the cap member so that the magnet means cannot be magnetically engaged thereon to hold the damper in an open position; and (c) it serves as a stiftening member for the damper.

With these remarks in mind, the principle objects of the present invention include:

To provide a forced iiow ventilator having freely pivotal dampers which seal the gas passageways when the fan is not operating;

To provide a force flow ventilator having freely pivotal dampers including magnet means secured thereon whose strength is suiiicient to hold the damper in sealing relation with the gas passageway only when the fan is not operating;

To provide a forced ow ventilator having freely pivotal dampers which pivot outwardly under the inuence of the gases discharged from the stack;

To provide a forced ow ventilator which is relatively inexpensive to manufacture and install; and

To provide a force ow ventilator wherein `only the cap member need be removed in order to service the fan and drive means.

ICC

These and other objects and advantages of the present invention will become apparent from the following detailed description by reference to the accompanying drawings in which:

FIGURE 1 is a cross-sectional view, taken along the line 1-1 of FIGURE 2, illustrating the interior structure of the present ventilator;

FIGURE 2 is a plan view, drawn on a smaller scale, of the ventilator of FIGURE l illustrating a cap member;

FIGURE 3 is a cross-sectional view, drawn on a smaller scale, taken along the line 3-3 of FIGURE 1, illustrating a stack of the present ventilator; and

FIGURE 4 is a fragmentary isometric view illustrating a freely pivotal damper and associated magnet means engaged with a vertical support member.

General Referring to FIGURE l, a generally horizontal roof of a buliding is indicated by the numeral 10. The roof 10 is constructed of structural elements 12 which may include concrete, metal beams, lumber or similar materials of construction. An opening 14, usually of rectangular configuration, is provided in the roof 10. The opening 14 is surrounded by a curbing 16 which extends above the upper level -of the roof 10. A weatherproof coating or surface 18 is provided above the structural elements 12 to Iserve as a weather-proong skin over the exposed surface of the building. The coating 18 may comprise tile, cement, bituminous materials, asbestos materials and the like.

The present force flow ventilator is indicated by the numeral 20 and generally comprises a stack 22, vertical support members 24, a cap member 26, gas passageways 27, and dampers 2S which have magnet means 29 secured thereto and which seal the gas passageways 27.

Stack 22 Referring to FIGURES 1 and 3, the stack 22 is adapted to surround the curbing 16 of the opening 14 and comprises a curb adapter 30, a fan housing 32 and a weathering skirt 34. The curb adapter 30 rests on the curbing 16 and is secured thereto by any suitable means. The fan housing 32 extends downwardly through the curb adapter 30 and into the opening 14. The fan housing 32 is secured to the curb adapter 30 preferably by means of bolts 35 and includes an outwardly extending ange 36 which rests lon the upper edge of the curb adapter 30. The weathering `skirt 34 comprises a vertical portion 37 which is secured to the vertical supports 24 preferably by means of bolts 39. The vertical portion 37 terminates along its upper edge in an external flange 40 and terminates along its lower edge in a generally L-shaped flange 41 having one leg thereof resting on and secured to the flange 36 preferably by means of bolts 38.

Comparing FIGURES 1 and 3 it will be seen that the stack 22 is defined by a plurality lof connected vertical side walls generally designated by the numeral 42 each of which comprises one of the weathering skirts 34, one vertical leg of the fan housing 32 and a vertical wall 43 of the curb adapter 30. In this instance the stack 22 has a square cross-section. It should be evident, however, that the stack 22 instead could have a hexagonal, octagonal or other polygon cross-section or even may have a circular cross-section since all of these cross-sections fall within the definition of a stack dened by a plurality of connected vertical side walls.

A drive means or electric motor 44 is mounted centrally in the fan housing 32 by means `of a T-shaped motor support 46. The motor 44 drives a fan 48 about a xed vertical axis so that the gases are drawn from the interior of the building through the opening 14 and the stack 22. A diaphragm 50, ysecured within the fan housing 32 at `the level of the fan 48, serves to increase the efllciency of the fan 48.

Vertical support members 24 Each of the vertical support members 24 extend upwardly from a corner 52 of the stack 22 (see FIGURE 3) which in the specification and the claims will be termed a juncture of the adjacent ones of the vertical side walls 42. Specifically the vertical support members 24 are secured at their lower ends to the weathering skirt` Cap member 26 Referring to FIGURES 1 and 2, the cap member 26 has a generally horizontal top 54 and a plurality of downwardly sloped connected side walls 56 which terminate at substantially the same level as the external flange 40 of the stack 22. Comparing FIGURES 1 and 2, the cap member 26 is frusto-pyramidal in shape and has a square horizontal cross-section. It should be evident, however, that the cap member 26 instead could have a hexagonal, octagonal or other polygon cross-section or may even have a circular crossasection since all of these cross-sections may be described as a plurality of downwardly sloped connected side walls. Preferably the number lof downwardly sloped connected side Walls 56 of the cap member 26 is equal to the number of vertical connected side walls 42 of the stack 22.

The cap member 26 is secured to the upper ends of the vertical support members 24 preferably by means of bolts 58. Thus the cap member 26 may be readily removed when the motor 44 of the fan 48 requires servicing.

Gas passageways 27 Referring to FIGURES 1 and 3, each gas passageway 27 is disposed between one adjacent pair `of the vertical support members 24 and above the external flange 40 and below the cap member 26. Actually, the peripheral edge of each gas passageway 27 comprises the adjacent pair of vertical support members 24, that portion of the external flange 40 and that portion of the inner surface of the cap member 24 which extend between the adjacent pair of vertical support members 24. In the illustrated ventilator there are four gas passageways 27.

Dampers 28 Referring to FIGURES 1 and 4, the dampers 28 are provided to seal the gas passageways 27 when the fan 48 is not operating. The dampers 28 are positioned externally of the gas passageway 27 and are freely pivoted along their upper edge 60 to the adjacent pair of vertical support members 24 by means of a rod 62 extending through an ear 64 secured to each of the support members 24.

The dampers 28 preferably are fabricated from lightweight, relatively thin gauge aluminum and hence include an outwardly extending flashing member 66 which serves to stillen the damper 28. The outwardly extending flashing member 66 also serves the second function of sealing the lower portion of the gas passageway 27 by engaging the external flange 40 of the stack 22 as shown in FIGURE 4. The position, indicated by the letter A in FIGURE 4, is the normally closed position of the damper 28 when the fan 48 is not operating.

When the fan 48 is operating, the damper 28, being lightweight, is forced outwardly to ride on the gas stream issuing from the gas passageway 27, in the position indicated by the letter B in FIGURE l.

Magnet means 29 Still referring to FIGURES l and 4, the dampers 28 have magnet means 29 secured thereto which are adapted to be attracted to portions of the ventilator structure surrounding the gas passageway 27. As specifically illustrated, each magnet means 29 is secured to the external surface of the damper 28 adjacent a side 68 thereof which overlies one of the vertical support members 24. The vertical support members 24 preferably comprise a magnetically susceptible material. The magnet means 29 preferably are positioned at the lower edge of the damper 28 adjacent to the flashing member 66 as shown in FIGURE 4.

The magnet means 29 should be of suflicient strength to maintain the damper 28 in sealing relation with the gas passageway 27 only when the fan 48 is not operating. When the fan is operating, sufficient gas pressure is built up within the ventilator 20 to overcome the magnetic attraction of the magnet means 29. The damper 28 thus is released and floats in the general position indicated at B in FIGURE 1.

At the left hand side of FIGURE 1, the damper 28 is also illustrated in the extreme outward position indicated by the letter C. In this position, the flashing member 66 serves the third function of a spacer, i.e., it maintains the damper 28 spaced from the side wall 56 of the cap member 26. Thus the magnet means 29 cannot magnetically engage the side wall 56 to hold the damper 28 in an open position.

From the foregoing detailed description it should be evident that the present invention provides a forced flow ventilator having freely pivotal dampers which seal the gas passageways when the fan is not operating; which pivot outwardly under the influence of the gas discharged from the stack; and which have magnet means secured thereon whose strength is sufficient to hold the dampers in sealing relation with the gas passageways only when the fan is not operating. The present invention further provides a forced flow ventilator which is relatively inexpensive to manufacture and install; and wherein only the cap member need be removed when the fan and drive means require servicing.

We claim:

1. A ventilator comprising in combination:

a ventilator stack adapted to surround a curb of a ventilator opening in a roof of a building, said stack being defined by a plurality of connected vertical flat side walls, said stack terminating in an external flange at the upper edge thereof;

a fan mounted within the said stack for rotation about a fixed vertical axis;

drive means for rotating the said fan;

a vertical support member extending upwardly from each juncture of adjacent ones of said vertical side walls;

means for securing said support member to said adjacent ones of said vertical side walls;

a cap member secured to the upper ends of said vertical support members and having a plurality of downwardly sloped connected side walls terminating at substantially the same level as said external flange and spaced therefrom;

a gas passageway between at least one adjacent pair of said vertical support members and above the said external flange and below the said cap member;

a damper disposed externally of the said gas passageway, said damper being substantially the same size as said gas passageway;

hinge means mounted at the junction of said vertical support members and said cap member beneath the said downwardly sloped connecting side walls, said hinge means pivotally securing said damper at its upper edge; and

an outwardly extending flashing member along the bottom edge of said damper, said flashing member being engaged with a portion of said external flange when the said fan is not operating.

2.` The ventilator of claim 1 wherein the said ventilatorV stack has a square cross-section.

3. The ventilator of claim 1 wherein the said cap member has a frusto-pyramidal shape.

4. The ventilator of claim 1 including:

magnet means secured to the external surface of the said damper and adapted to be attracted to portions of the structure surrounding the said gas passage- Way;

said damper comprising a non-magnetic material;

said magnet means being so positioned and being of suicient strength to hold the said damper in sealing relation with the said gas passageway only when the said fan is not operating.

5. The ventilator of claim 1 including:

magnet means secured along those sides of said damper which overlie the said adjacent pair of said vertical support members;

said damper comprising a non-magnetic material; and

the said adjacent pair of vertical support members comprising magnetic susceptible material;

said magnet means being so positioned and being of suicient strength to hold the said damper in sealing relation with the said gas passageway only when the said fan is not operating. 6. The ventilator of claim 1 wherein the said hinge means are mounted to the upper ends of the said vertical 5 support members.

References Cited by the Examiner UNITED STATES PATENTS EDWARD I. MICHAEL, Primary Examiner.

ROBERT A. OLEARY, Examiner. 

1. A VENTILATOR COMRPRISING IN COMBINATION: A VENTILATOR STACK ADAPTED TO SURROUND A CURB OF A VENTILATOR OPENING IN A ROOF OF A BUILDING, SAID STACK BEING DEFINED BY A PLURALITY OF CONNECTED VERTICAL FLAT SIDE WALLS, SAID STACK TERMINATING IN AN EXTERNAL FLANGE AT THE UPPER EDGE THEREOF; A FAN MOUNTED WITHIN THE SAID STACK FOR ROTATION ABOUT A FIXED VERTICAL AXIS, DRIVE MEANS FOR ROTATING THE SAID FAN; A VERTICAL SUPPORT MEMBER EXTENDING UPWARDLY FROM EACH JUNCTURE OF ADJACENT ONES OF SAID VERTICAL SIDE WALLS; MEANS FOR SECURING SAID SUPPORT MEMBER TO SAID ADJACENT ONES OF SAID VERTICAL SIDE WALLS; A CAP MEMBER SECURED TO THE UPPER ENDS OF SAID VERTICAL SUPPORT MEMBERS AND HAVING A PLURALITY OF DOWNWARDLY SLOPED CONNECTED SIDE WALLS TERMINATING AT SUBSTANTIALLY THE SME LEVEL AS SAID EXTERNAL FLANGE AND SPACED THEREFROM; A GAS PASSAGEWAY BETWEEN AT LEAST ONE ADJACENT PAIR OF SAID VERTICAL SUPPORT MEMBERS AND ABOVE THE SAID EXTERNAL FLANGE AND BELOW THE SAID CAP MEMBER; A DAMPER DISPOSED EXTERNALLY OF TE SAID GAS PASSAGEWAY, SAID DAMPER BEING SUBSTANTIALLY THE SAME SIZE AS SAID GAS PASSAGEWAY; HINGE MEANS MOUNTED AT THE JUNCTION OF SAID VERTICAL SUPPORT MEMBERS AND SAID CAP MEMBER BENEATH THE SAID DOWNWARDLY SLOPED CONNECTING SIDE WALLS, SAID HINGE MEANS PIVOTALLY SECURING SAID DAMPER AT ITS UPPER EDGE; AND AN OUTWARDLY EXTENDING FLASHING MEMBER ALONG THE BOTTOM EDGE OF SAID DAMPER, SAID FLASHING MEMBER BEING ENGAGED WITH A PORTION OF SAID EXTERNAL FLANGE WHEN THE SAID FAN IS NOT OPERATING. 